There are three main types of cloning; 1) Recombinant DNA technology 2) Reproductive cloning 3) Therapeutic cloning.
Recombinant DNA Technology.
Is the transfer of a DNA fragment of interest from one organism to a self replicating genetic element such as a bacterial plasmid.
This type of technology has been around since the 1970's and was used by the human genome project researchers to copy genes and other pieces of chromosomes to generate enough identical material for study.
A technology used to generate an animal that has the same nuclear DNA as the primary source.
Dolly is the most widely known example of this type of cloning she was the first mammal to be cloned from adult DNA, born in 1996 died in 2003 after being bred and delivering six lambs.
The production of human embryos for use in research and to harvest stems cells.
Stem cells are important because they can be used to generate virtually any type of specialised cell in the human body.
It is hoped that one day that stem cells may be used to treat heart disease, Alzheimer's and cancer.
In both therapeutic and reproductive cloning, the start of the process is the sam; the nucleus from a single egg is removed and DNA from another cell is placed into it an electric current; or chemicals are used to kick start the cell into dividing, once it has divided to approximately 100 cells it can be implanted and brought to term, this last part is what happens in reproductive cloning. In therapeutic cloning once a very early embryo is formed, stem cells are extracted for medical research and the embryo is destroyed.
The whole issue of cloning has thrown up a lot of ethical questions but like a lot of things in life there is not always a clear line between what is right and wrong.
With reproductive cloning there is a possibility that one day a human being could be cloned (although unlikely given its current failure rate); this in my opinion is too close for comfort.
Recombinant DNA cloning is a useful research tool. Therapeutic cloning could hold the answers to treating many currently incurable devastating and deadly diseases/disorders, and possibly solve the shortage of suitable organs available for transplant.
Ethically, therapeutic cloning in particular has seen opposition from many pro- lifers; the question is when does human life begin? At fertilisation, birth or somewhere in between?
Within cloning technology I believe there is the potential for both harm and good.
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